Charging base



FIG. 1 is a perspective view of an charging base showing my new design;

FIG. 2 is another perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a back elevation view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

The broken lines in the drawing depict environmental subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for an charging base, as shown and described. 